Entrants jump, fly or launch themselves off Bognor Pier in West Sussex in the hope of winning £25,000.

Duncan does have some relevant experience as he is a keen hang-glider and is a member of the Peak Soaring Club.

But the magnificent man isn't going to take to the air on one of those - he's building his own flying machine.

He said: "I heard about the Bognor Birdman through a friend and thought 'that sounds like a really good idea' - like you do.

"People have told me I'm mad. I also thought it would be a good way to raise money for charity."

Duncan, who is an engineer at AstraZeneca, will be raising money through sponsorship for Macmillan Cancer Relief.

He said: "I've got a good friend who was a hang-glider. Two or three years ago he was like a Greek god and had lots of pretty girls around him. Then he got throat cancer.

"At one time his days were numbered but Macmillan helped him quite a bit. I can see the results from that. It's a worthwhile thing."

Duncan has entered the Magnificent Flight category and hopes to reach the magical 300ft mark. But he's not going to use his hang-glider.

"I am going to build my own glider based on the Wright brothers," he said.

As Duncan lives on a farm he has plenty of space to build his flying machine. It will have twisting wings and work with bicycle brake levers. Because Duncan will be sitting in the machine safety is of paramount importance.

"Hang gliding is perfectly safe, it's hitting the floor that hurts - or the sea," he said.

"I will have a life jacket because I'm strapped in but some people just jump of the end of the pier or have a glider that falls off in bits. Someone even jumped off on an inflatable elephant. It's a 30ft drop."

After looking at the Birdman website and watching video clips of some of the bird-brained entrants Duncan is beginning to wonder what he's let himself in for.

"My family think I'm mad," he said. "And I hang-glide with three other lads who are interested in what I'm planning but they keep saying 'Do you really want to do this?' But I've had my confirmation now so I can't back out.

"There's a hill near my house so I will probably practise by running off that."

Organisers of the event are delighted with the number of serious entries.

John Stride from organisers, Arun District Council, said: "After 24 years of Birdman, I think there is an excellent chance that the jackpot prize will be scooped this year.

"The majority of the 'magnificent flyers' entrants have aviation experience and the competition will be fierce as paraglider pilots, hang-gliding instructors and aeronautical engineers attempt to outwit and outmanoeuvre each other in a bid to claim the glory."

Anyone who wants to sponsor Duncan for the event, on August 11, can call him on 01625 575236.